Jerry Seinfeld and Larry David made millions by creating a sitcom about nothing (and everything). Now an Israeli has invented an app about nothing (or it might as well be) that is taking the world by storm.

“We’ve had a crazy, crazy day,” said Or Arbel, 32, about the 24 hours that transpired after his app Yo became the hottest thing on social networks, websites and blogs across the United States.

All the Yo app does is let you send the word “Yo” to your smartphone buddies, along with an amusing sound. That’s it, yet the app has been downloaded more than 100,000 times, reached the US App Store top 10 list this week, and the company who developed it has raised over a million dollars.

What is Yo? It’s whatever you want it to be, depending on the context, time and situation. Arbel, who spent two years working for Mobli, got the idea from that startup’s Israeli founder, Moshe Hogeg.

“Moshiko asked me to develop an app for him that would have just one big button that could send a push notification to his assistant,” says Arbel, who holds a degree in computer science from Ben-Gurion University of the Negev. He constantly needed her during the day and having to text or call was irksome, Arbel explains.

Keep updated: Sign up to our newsletter

Email*

Please enter a valid email address

Please wait…

Thank you for signing up.

Oops. Something went wrong.

Thank you,

The idea was that when the assistant got the push notification, she’d know he needed her. Arbel figured that other people with assistants might need an app like that too. He figured it would take him maybe two hours to develop such an app, but because he was deeply preoccupied with the startup Stox.com, a joint venture of his with Hogeg to develop gaming platforms, he rejected the request.

The dumbest thing he’d ever seen

Yet the next day, during a long ride, Arbel thought of a friend in Los Angeles with whom he regularly messaged through WhatsApp – without basically saying a thing.

“He’d send me a question mark and I’d answer with an exclamation mark, and sometimes he simply would send me the word Yo. I realized that I was basically communicating with someone in the way Moshiko wanted. I sat down Friday afternoon and by nighttime the app was ready,” Arbel says.

He sent it to a development group at Whatsapp, and wrote them, “Meet the zero characters communication tool.” Everyone got excited (save for one who said it was the dumbest thing he had ever seen in his life – and for that Steve Jobs is surely turning over in his grave).

In line with Hogeg’s request, Arbel designed the app with big, simple buttons.

“Everyone wanted me to add features, but I refused,” he says. “If you add more words, like ‘Good morning,’ ‘What’s up?’ and ‘Hello’ then the app only knows how to send these words. If you have only the word ‘Yo,’ then it has to be everything. If you want to send it in the morning, it’s basically ‘Good morning.’ If you send it in the middle of the day you are asking ‘What’s up?’ If your boss sends it to you he wants you to come, and if you send it at night you are basically asking ‘You up?’ It all depends on the time, the sender and the context.”

They decided to release the app to the App Store, and people slowly started hearing about it. The first serious buzz happened when blogger ad technical Robert Scoble wrote about Yo after a visit to Israel. He called it “the stupidest” but “most addicting” app.

Thus the Yo app became the conversation of the day among the startup crowd in Silicon Valley and New York, who tweeted how excited they were at using it. As interest burgeoned, Arbel moved to San Francisco last week.

News sites started reporting on Yo in droves and downloads doubled overnight.

Yo, you have a story

Arbel says the flippant Yo has a serious future. “It has tons of uses, more than you might think. Our next stage is to bring out a programming interface so developers can integrate with our app and other bodies can use our service,” he says. “Say, for example, Haaretz decides that anyone connected to it through Yo should get a Yo every time there is breaking news – it could bring you a lot of engagement. Modification is very simple. It is not like a complicated text you have to open and read. If the story grabs your interest, you’ll check the website.”

Yo created the username WorldCup on the occasion of the international soccer competition to demonstrate this possibility. Anyone joining this handle receives a Yo message every time a goal is scored. Arbel also says coffee chains could send customers a Yo instead of calling their names out, airports could tell passengers to start boarding with a Yo and fashion companies could send out a Yo to announce a sale.

Twitter is already filled with excited users, who write to Yo’s profile, called @YoAppStatus.

“I’ve been using the Yo app for weeks and I think it’s brilliant in its simplicity of design and function. Steve Jobs would be proud,” wrote @BPLewis, and @internetrebecca added: “The Yo app makes more sense than most things in this world.”

So what are you waiting for? Yo!

Founder of Yo, Or Arbel.CourtesyScreenshot of the Yo app.CourtesyScreenshot of the Yo app.Screenshot of the Yo app.Courtesy

Haaretz.com, the online edition of Haaretz Newspaper in Israel, and analysis from Israel and the Middle East. Haaretz.com provides extensive and in-depth coverage of Israel, the Jewish World and the Middle East, including defense, diplomacy, the Arab-Israeli conflict, the peace process, Israeli politics, Jerusalem affairs, international relations, Iran, Iraq, Syria, Lebanon, the Palestinian Authority, the West Bank and the Gaza Strip, the Israeli business world and Jewish life in Israel and the Diaspora.